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Protective mechanism of L-arginine against liver ischemic-reperfusion injury in rats

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Hepatobiliary & Pancreatic Diseases International 2003年第4期2卷 549-552页

作者： Shao-Qiang Li Li-Jian Liang the department of Hepatobiliary Surgery, First Affiliated Hospital, sun yat-sen university, Guangzhou {2., china department of Hepatobiliary Surgery First Affiliated Hospital Sun Yat-Sen University Guangzhou 510080 China. lesq@***

OBJECTIVE: To investigate the protective effect of L-arginine (L-arg) against liver ischemic-reperfusion (I/R) injury in rat model and its possible mechanism. METHODS: Male Sprague-Dawley rats were randomized into sham group: hepatoduodenal ligament mobilized, but not clamped; control group: hepatic ischemia only; Arg group: 5 minutes before hepatic ischemia, L-arg (2.0 mg/kg) injected via the dorsal penis vein; Arg+L group: 10 and 5 minutes before hepatic ischemia, L-NAME (30 mg/kg) and L-arg (2.0 mg/kg) injected via the dorsal penis vein, respectively; and Fink group: 5 minutes before, hepatic ischemia, ZVAD-fmk (15 mg/kg) injected via the dorsal penis vein. The liver was subjected to ischemia for 40 minutes by Pringle's maneuver, and reperfusion was initiated hy removing clamp. The 7-day survival rate, alanine transaminase (ALT) level, caspase-3 activity and apoptotic hepatocyte count were compared among these groups. RESULTS: After 40 minutes of ischemia and 6 hours of reperfusion, the 7-day survival rate of the Arg group was significantly higher than that of the control and Arg+L groups (P3 activity and apoptotic hepatocyte count in the Arg group were decreased significantly than those in the control and Arg+L groups (P3 activity and apoptotic hepatocyte count in the Arg group were slightly higher than those in the sham and Fmk groups, but there was no statistical significance. CONCLUSIONS: L-arg could ameliorate liver I/R injury and the possible protective mechanism is inhibition of hepatocyte apoptosis via inhibition of caspase-3 activity by nitric oxide synthesis.

关键词： liver ischemia nitirc oxide caspase-3 rat

MANIFOLDS WITH POINTWISE PINCHED RICCI CURVATURE

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Acta Mathematica Scientia 2010年第3期30卷 819-829页

作者：顾会玲 department of Mathematics Sun Yat-sen University

In this article, the author proves a compactness result about Riemannian manifolds with an arbitrary pointwisely pinched Ricci curvature tensor.

关键词： Ricci pinching condition Yamabe flow asymptotic behavior

A Deniable Authenticated Key Agreement Protocol

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Wuhan university Journal of Natural Sciences 2008年第6期13卷 645-650页

作者： TIAN Haibo1,2. CHEN Xiaofeng1,2. ZHANG Fangguo1,2. WEI Baodian1,2.1. school of Information Science and Technology, sun yat-sen university, Guangzhou 510006, Guangdong,{2. 2. Guangdong Key Laboratory of Information Security Technology, sun yat-sen university, Guangzhou 5102.5, Guangdong,{2. school of Information Science and Technology Sun Yat-Sen University Guangzhou 510006 Guangdong China Guangdong Key Laboratory of Information Security Technology Sun Yat-Sen University Guangzhou 510275 Guangdong China

This paper presents a deniable authenticated key agreement protocol. This protocol can provide an authenticated session key while the sender and the receiver can deny their involvement in such a protocol if the protocol is executed successfully. Then both can deny their transmitted messages protected by the authenticated session key. If this protocol fails, no authenticated session key can be established and no protected messages can be transmitted. The protocol can be proved secure against key compromise impersonation attack. The protocol employs a new method to isolate a session key from confirmation keys.

关键词： deniable authentication key agreement key compromise impersonation

NUMERICAL MODELING OF WAVE EVOLUTION AND RUNUP IN SHALLOW WATER

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Journal of Hydrodynamics 2009年第6期21卷 731-738页

作者： DONG Zhi ZHAN Jie-min department of Applied Mechanics and Engineering Sun Yat-sen University Guangzhou 510275 China Guangdong Province Key Laboratory of Coastal Ocean Engineering Sun Yat-sen University Guangzhou 510275China

Based on the Navier-Stokes （N-S） equations for viscous, incompressible fluid and the VOF method, 2.D and 3-D Numerical Wave Tanks （NWT） for nonlinear shallow water waves are built. The dynamic mesh technique is applied, which can save computational resources dramatically for the simulation of solitary wave propagating at a constant depth. Higher order approximation for cnoidal wave is employed to generate high quality waves. Shoaling and breaking of solitary waves over different slopes are simulated and analyzed systematically. Wave runup on structures is also investigated. The results agree very well with experimental data or analytical solutions.

关键词： VOF method shallow water waves wave evolution wave runup

Geometric phase-encoded stimuli-responsive cholesteric liquid crystals for visualizing real-time remote monitoring:humidity sensing as a proof of concept

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Light(Science & Applications) 2024年第2期13卷 283-293页

作者： Shi-Long Li Zhao-Yi Chen Peng Chen Wei Hu Chaohong Huang sen-sen Li Xuejia Hu Yan-Qing Lu Lu-Jian Chen department of Electronic Engineering School of Electronic Science and EngineeringXiamen University361005 XiamenChina College of Engineering and Applied Sciences Nanjing University210093 NanjingChina Fujian Key Laboratory of Ultrafast Laser Technology and Applications Xiamen University361005 XiamenChina

Liquid crystals are a vital component of modern photonics,and recent studies have demonstrated the exceptional sensing properties of stimuli-responsive cholesteric liquid ***,existing cholesteric liquid crystal-based sensors often rely on the naked eye perceptibility of structural color or the measurement of wavelength changes by spectrometric tools,which limits their practical ***,developing a platform that produces recognizable sensing signals is *** this study,we present a visual sensing platform based on geometric phase encoding of stimuli-responsive cholesteric liquid crystal polymers that generates real-time visual patterns,rather than frequency *** demonstrate this platform’s effectiveness,we used a humidity-responsive cholesteric liquid crystal polymer film encoded with a q-plate pattern,which revealed that humidity causes a shape change in the vortex beam reflected from the encoded cholesteric liquid crystal ***,we developed a prototype platform towards remote humidity monitoring benefiting from the high directionality and long-range transmission properties of laser beams carrying orbital angular *** approach provides a novel sensing platform for cholesteric liquid crystals-based sensors that offers promising practical *** ability to generate recognizable sensing signals through visual patterns offers a new level of practicality in the sensing field with stimuli-responsive cholesteric liquid *** platform might have significant implications for a broad readership and will be of interest to researchers working in the field of photonics and sensing technology.

关键词： humidity visual liquid

Marine compound Xyloketal B improves endothelial function and decreases atherosclerotic lesion formation in apolipoprotein E-/- mice

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Marine compound Xyloketal B improves endothelial function an...

Some basic principles for the linear theory of piezoelectric micropolar elastodynamics

第八届海峡两岸心血管科学研讨会

作者： Yun-ying Huang~1,Jian-wen Chen~2.Yu Xie~1,Hong-mei Tan~3,Jie Liu~1,Guan-lei Wang~1 (1.department of Pharmacology,zhongshan {2. of medicine,sun yat-sen university, Guangzhou 510080,china 2.department of Pharmacology and Toxicology,{2. of Pharmaceutical Sciences,sun yat-sen university,HEMC,Guangzhou 510006,china 3.department of Pathophysiology, zhongshan school of medicine,sun yat-sen university,Guangzhou 510080,china)

Objective Xyloketal B is a novel marine compound with unique chemical structure isolated from mangrove fungus Xylaria sp.(No.2.08).Our recent studies have demonstrated it can relax the phenylephrine -induced contraction of rat thoracic aorta rings through endothelium-dependent and independent manners, protect against oxLDL-induced endothelial oxidative injury probably through inhibiting ROS generation and promoting NO *** present study was designed to test whether xyloketal B can decreases atherosclerotic lesion formation and improve endothelial function through Akt/eNOS signaling *** and Materials Changes in isometric tension were measured in rat aortic *** total expression of endothelial NOS(eNOS) and Akt,phosphorylation of eNOS and Akt was assayed by Western blot *** area was quantified by histology in apolipoprotein E-deficient(ApoE ) *** In rings with endothelium, xyloketal B inhibited contractile responses to PE and improved the relaxation responses to acetylcholine (ACh).Xyloketal B had no effects on total protein expression of eNOS and *** B caused an increase in eNOS phosphorylation at Ser1177 and a decrease in phosphorylation at Thr495;and it enhanced the phosphorylation of Akt at Ser473.A 16 -week treatment with xyloketal B reduced atherosclerotic plaque formation in aorta and aortic sinus of ApoE *** These results suggest that xyloketal B decrease atherosclerotic plaque formation in ApoE mice,which may be associated with promoting endothelial function through regulating phosphorylation of eNOS at Thr495 and Ser1177 and Akt Ser473.

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中国科学：物理学、力学、天文学英文版 2010年第6期53卷 1094-1100页

作者： LUO En & LI WeiHua department of Applied Mechanics and Engineering,sun {2.-sen university,Guangzhou 5102.5,china 1. department of Applied Mechanics and Engineering Sun Yat-sen University Guangzhou 510275 China

According to the basic idea of classical yin-yang complementarity and modern dual-complementarity,in a simple and unified way proposed by Luo,some basic principles in the linear theory of piezoelectric micropolar elastodynamics can be established systematically. In this paper,an important integral relation in terms of convolutions is given,which can be considered as the generalized principle of virtual work in mechanics. Based on this relation,it is not only possible to obtain the principle of virtual work and the reciprocal theorem,but also to systematically derive the complementary functionals for the eleven-field,nine-field and six-field simplified Gurtin-type variational principles and the potential energy-functional for the three-field one in the linear theory of piezoelectric micropolar elastodynamics by the generalized Legendre transformations given in this paper. Furthermore,with this approach,the intrinsic relationships among various principles can be explained clearly.

关键词： piezoelectric micropolar elastodynamics principle of virtual work reciprocal theorem simplified Gurtin-type variational principle complementary relation

Spatial calculating analysis model research of land-use change in urban fringe districts

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Science china(Technological Sciences) 2008年第S1期51卷 186-194页

作者： ZHANG XinChang,PAN Qiong,WANG ZhongYang & CHEN XinXiang department of Remote sensing and GIS Engineering,{2. yat-sen university,Guangzhou 5102.5,china department of Remote sensing and GIS Engineering Sun Yat-sen University Guangzhou 510275 China

The spatial calculating analysis model is based on GIS overlay. It compartmental-izes the research district land into three spatial parts: unchanged part,converted part and increased part. By this method we can evaluate the numerical model and dynamic degree model for existing calculating changing speed of land-use. Fur-thermore the paper raises reviving the calculating analysis model of spatial infor-mation in order to predict the dynamic changing level of all sorts of land. More concretely speaking,the model is mainly to know the changing area and changing speed (increased or decreased) of different land classifications from the micro-cosmic angle and to clearly show the spatial distribution and spatio-temporal law for changing urban lands. We discover why the situation has taken place by com-bining social and economic conditions. The result indicates that the calculating analysis model of spatial information can derive more accurate procedure of spatial transference and increase of all kinds of land from the microcosmic angle. By this model and technology,we can make the research of spatio-temporal structure evolution in land-use be more systematical and deeper. The result will benefit the planning management of urban land-use of developed districts in china in the fu-ture.

关键词： land-use dynamic change calculating analysis model

17β-estradiol enhances breast cancer cell motility and invasion via extra-nuclear activation of actin-binding protein ezrin N

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17β-estradiol enhances breast cancer cell motility and inva...